A super heroic discussion of "Absolute Power - Book Two: Essentials" perhaps?

I initially did not even realize that Absolute Power was the new version of Silver Age Sentinels - perhaps they wanted to avoid confusion with Sentinel City, a DIFFERENT Superhero TTRPG? In any case, I've studied book one fairly thoroughly, but it feels like they stretched this one out into two core books, where in prior editions it was a single core book format.
If anyone familiar with the second Absolutely Power core book, entitled "Absolute Power - Book Two: Essentials," to discuss what material is in this second book that was not contained in the first AP book? Very curious to hear others' takes, whether here, or via DM, per your preference.